Selective radical cascade (4+2) annulation with olefins towards the synthesis of chroman derivatives organo-photoredox catalysis.

Due to the importance of chroman frameworks in medicinal chemistry, the development of novel synthetic methods for these structures is gaining increasing interest of chemists. Reported here is a new (4 + 2) radical annulation approach for the construction of these functional six-membered frameworks photocatalysis. Featuring mild reaction conditions, the protocol allows readily available -hydroxyphthalimide esters and electron-deficient olefins to be converted into a wide range of valuable chromans in a highly selective manner.

Stereodivergent synthesis of enantioenriched azepino[3,4,5-]-indoles cooperative Cu/Ir-catalyzed asymmetric allylic alkylation and intramolecular Friedel-Crafts reaction.

The development of enantioselective annulation reactions using readily available substrates for the construction of structurally and stereochemically diverse heterocycles is a compelling topic in diversity-oriented synthesis. Herein, we report efficient catalytic asymmetric formal 1,3-dipolar (3 + 4) cycloadditions of azomethine ylides with 4-indolyl allylic carbonates for the construction of azepino[3,4,5-]-indoles fused with a challenging seven-membered N-heterocycle, a frequently occurring tricyclic indole scaffold in bioactive compounds and pharmaceuticals. Through cooperative Cu/Ir-catalyzed asymmetric allylic alkylation followed by intramolecular Friedel-Crafts reaction, an array of azepino[3,4,5-]-indoles were obtained in good yields with excellent diastereo-/enantioselective control.

NiSe/NiSe on nickel foam as an ultra-high-rate HER electrocatalyst: common anion heterostructure with built-in electric field and efficient interfacial charge transfer.

One grand challenge in green hydrogen production is to design efficient HER electrocatalysts for high-rate alkaline water electrolysis. Nickel chalcogenide coatings on nickel foam (NF) are promising HER electrocatalysts, but their high-rate performances are yet to be improved. The current work reports a NiSe/NiSe@NF for alkaline HER, which requires an overpotential of only 336 mV to achieve an ultra-high current density of 1250 mA cm, outperforming commercial Pt/C.

Enhanced adsorption-based atmospheric water harvesting using a photothermal cotton rod for freshwater production in cold climates.

Solar energy-powered adsorption-based atmospheric water harvesting (ABAWH) is an emerging technology for freshwater production, especially in water-scarce regions that are remote and landlocked. Numerous water adsorbents have been used in ABAWH devices to convert molecule to liquid water. However, it is still challenging to harvest water from the air in cold winter, owing to the water adsorption of sorbents decreasing significantly at low temperature.

Vertically stacked GaN/WX (X = S, Se, Te) heterostructures for photocatalysts and photoelectronic devices.

Tremendous attention has been paid to vertically stacked heterostructures owing to their tunable electronic structures and outstanding optical properties. In this work, we explore the structural, electronic and optical properties of vertically stacked GaN/WX (X = S, Se, Te) heterostructures using density functional theory. We find that these stacking heterostructures are all semiconductors with direct band gaps of 1.

Gold nanoclusters as a GSH activated mitochondrial targeting photosensitizer for efficient treatment of malignant tumors.

Gold nanoclusters (Au NCs), which have the characteristics of small size, near infrared (NIR) absorption and long triplet excited lifetime, have been used as a new type of photosensitizer for deep tissue photodynamic therapy (PDT). However, the therapeutic efficiency of the nano-system based on Au NCs still needs to be improved. Herein, we proposed a strategy using Mito-Au@MnO nanocomposites to achieve enhanced PDT.

Catalytic asymmetric synthesis of enantioenriched α-deuterated pyrrolidine derivatives.

The recent promising applications of deuterium-labeled pharmaceutical compounds have led to an urgent need for the efficient synthetic methodologies that site-specifically incorporate a deuterium atom into bioactive molecules. Nevertheless, precisely building a deuterium-containing stereogenic center, which meets the requirement for optimizing the absorption, distribution, metabolism, excretion and toxicity (ADMET) properties of chiral drug candidates, remains a significant challenge in organic synthesis. Herein, a catalytic asymmetric strategy combining H/D exchange (H/D-Ex) and azomethine ylide-involved 1,3-dipolar cycloaddition (1,3-DC) was developed for the construction of biologically important enantioenriched α-deuterated pyrrolidine derivatives in good yields with excellent stereoselectivities and uniformly high levels of deuterium incorporation.

In Situ Microreaction Platform Based on Acoustic Droplet Manipulation for Ultra-High-Precision Multiplex Bioassay.

Liquid droplets rectors have been used in clinical diagnosis, high throughput screening and bioassay. However, it is challenging for droplet reactors to be used in practical applications due to the difficulty of uniformly mixing ultrasmall volumes of samples and the lack of rapid and high-precision detection protocols. Here, we have developed an acoustic droplet system for rapid and efficient biological detection and chemical screening.

Glucose hydrothermal encapsulation of carbonized silicone polyester to prepare anode materials for lithium batteries with improved cycle stability.

A silicon polyester (Si-PET) was synthesized with ethylene glycol and phthalic anhydride, and then it was carbonized and hydrothermally coated with glucose. The formed SiO with layered graphene as the 3D network had an amorphous carbon layer. The graphene oxide (rGO) after carbothermal reduction was completely retained in SiO , which improved the conductivity of the SiO anode material.

Gas permeation and microstructure of reduced graphene oxide/polyethyleneimine multilayer films created recast and layer-by-layer deposition processes.

Nowadays, graphene/polymer composite films with multilayer structure have attracted significant attention for gas barrier application. In this study, a series of reduced graphene oxide/polyethyleneimine (RGO/PEI) composite films were created recast and layer-by-layer deposition processes. By using the recast process, the myriad PEI molecules in the precursor solution (the PEI : GO feeding ratio is 0.

Theoretical hydrogen bonding calculations and proton conduction for Eu(iii)-based metal-organic framework.

A water-mediated proton-conducting Eu(iii)-MOF has been synthesized, which provides a stable proton transport channel that was confirmed by theoretical calculation. The investigation of proton conduction shows that the conductivity of Eu(iii)-MOF obtained at 353 K and 98% RH is 3.5 × 10 S cm, comparable to most of the Ln(iii)-MOF based proton conductors.

Electrochemical oxidative N-H/P-H cross-coupling with H evolution towards the synthesis of tertiary phosphines.

Tertiary phosphines(iii) find widespread use in many aspects of synthetic organic chemistry. Herein, we developed a facile and novel electrochemical oxidative N-H/P-H cross-coupling method, leading to a series of expected tertiary phosphines(iii) under mild conditions with excellent yields. It is worth noting that this electrochemical protocol features very good reaction selectivity, where only a 1 : 1 ratio of amine and phosphine was required in the reaction.

Paired electrolysis enabled annulation for the quinolyl-modification of bioactive molecules.

A paired electrolysis enabled cascade annulation that enables the efficient synthesis of highly functionalized quinoline-substituted bioactive molecules from readily available starting materials is reported. Using this methodology, two goals, namely, the direct synthesis of quinolines and the introduction of quinoline moieties to bioactive molecules, can be simultaneously achieved in one simple operation. The use of electroreduction for the activation of isatin, together with the further anodic oxidation of KI to catalytically result in a cascade annulation, highlight the unique possibilities associated with electrochemical activation methods.

Synthesis of bioactive fluoropyrrolidines copper(i)-catalysed asymmetric 1,3-dipolar cycloaddition of azomethine ylides.

Chiral pyrrolidinyl units are important building blocks in biologically active natural products and drugs, and the development of efficient methods for the synthesis of diverse structured pyrrolidine derivatives is of great importance. Meanwhile, incorporating fluorine containing groups into small molecules often changes their activities to a great extent due to the special physicochemical properties of fluorine atoms. Herein, we report an efficient route to obtain enantioenriched 3,3-difluoro- and 3,3,4-trifluoropyrrolidinyl derivatives by Cu(i)-catalysed enantioselective 1,3-dipolar cycloaddition of azomethine ylides with less active 1,1-difluoro- and 1,1,2-trifluorostyrenes.

Nickel/Brønsted acid dual-catalyzed regio- and enantioselective hydrophosphinylation of 1,3-dienes: access to chiral allylic phosphine oxides.

While chiral allylic organophosphorus compounds are widely utilized in asymmetric catalysis and for accessing bioactive molecules, their synthetic methods are still very limited. We report the development of asymmetric nickel/Brønsted acid dual-catalyzed hydrophosphinylation of 1,3-dienes with phosphine oxides. This reaction is characterized by an inexpensive chiral catalyst, broad substrate scope, and high regio- and enantioselectivity.

An asymmetric 2,3-fluoranthene imide building block for regioregular semiconductors with aggregation-induced emission properties.

For organic semiconductors, the development of electron-deficient building blocks has lagged far behind that of the electron-rich ones. Moreover, it remains a significant challenge to design organic molecules with efficient charge transport and strong solid-state emission simultaneously. Herein, we describe a facile synthetic route toward a new π-acceptor imide building block, namely 2,3-fluoranthene imide, based on which four regioregular small molecules (F1-F4) are synthesized by tuning the imide orientations and the central linkage bridges.

Unexpected role of electronic coupling between host redox centers in transport kinetics of lithium ions in olivine phosphate materials.

The discrepancy between the trend in the diffusion coefficient of a lithium ion ( ) and that in the activation energy of ion hopping signals hidden factors determining ion transport kinetics in layered olivine phosphate materials (LiMPO). Combining density functional theory (DFT) calculations and the Landau-Zener electron transfer theory, we unravel this hidden factor to be the electronic coupling between redox centers of the host materials. The ion transport process in LiMPO is newly described as an ion-coupled electron transfer (ET) reaction, where the electronic coupling effect on is considered by incorporating the electronic transmission coefficient into the rate constant of the transfer reaction.

Stereodivergent synthesis iridium-catalyzed asymmetric double allylic alkylation of cyanoacetate.

Methods that enable the rapid construction of multiple C-C bonds using a single catalyst with high diastereo- and enantio-control are particularly valuable in organic synthesis. Here, we report an Ir-catalyzed double allylic alkylation reaction in which bisnucleophilic cyanoacetate reacted successionally with electrophilic π-allyl-Ir species, producing various -symmetrical cyanoacetate derivatives in high yield with excellent stereocontrol. More challenging sequential allylic alkylation/allylic alkylation with two distinct allylic carbonates that can deliver the corresponding products bearing three contiguous tertiary-quaternary-tertiary stereocenters was also developed by using a modified catalytic system, which is revealed to be associated with the -dynamic kinetic resolution of the initially formed diastereomeric monoallylation intermediates.

Correction: Plasticizer and catalyst co-functionalized PEDOT:PSS enables stretchable electrochemical sensing of living cells.

[This corrects the article DOI: 10.1039/D1SC04138J.].

Bioorthogonal regulation of DNA circuits for smart intracellular microRNA imaging.

Catalytic DNA circuits represent a versatile toolbox for tracking intracellular biomarkers yet are constrained with low anti-interference capacity originating from their severe off-site activation. Herein, by introducing an unprecedented endogenous DNA repairing enzyme-powered pre-selection strategy, we develop a sequential and specific on-site activated catalytic DNA circuit for achieving the cancer cell-selective imaging of microRNA with high anti-interference capacity. Initially, the circuitry reactant is firmly caged by an elongated stabilizing duplex segment with a recognition/cleavage site of a cell-specific DNA repairing enzyme, which can prevent undesired signal leakage prior to its exposure to target cells.

Intelligent demethylase-driven DNAzyme sensor for highly reliable metal-ion imaging in living cells.

The accurate intracellular imaging of metal ions requires an exquisite site-specific activation of metal-ion sensors, for which the pervasive epigenetic regulation strategy can serve as an ideal alternative thanks to its orthogonal control feature and endogenous cell/tissue-specific expression pattern. Herein, a simple yet versatile demethylation strategy was proposed for on-site repairing-to-activating the metal-ion-targeting DNAzyme and for achieving the accurate site-specific imaging of metal ions in live cells. This endogenous epigenetic demethylation-regulating DNAzyme system was prepared by modifying the DNAzyme with an mA methylation group that incapacitates the DNAzyme probe, thus eliminating possible off-site signal leakage, while the cell-specific demethylase-mediated removal of methylation modification could efficiently restore the initial catalytic DNAzyme for sensing metal ions, thus allowing a high-contrast bioimaging in live cells.

Plasticizer and catalyst co-functionalized PEDOT:PSS enables stretchable electrochemical sensing of living cells.

Recently, stretchable electrochemical sensors have stood out as a powerful tool for the detection of soft cells and tissues, since they could perfectly comply with the deformation of living organisms and synchronously monitor mechanically evoked biomolecule release. However, existing strategies for the fabrication of stretchable electrochemical sensors still face with huge challenges due to scarce electrode materials, demanding processing techniques and great complexity in further functionalization. Herein, we report a novel and facile strategy for one-step preparation of stretchable electrochemical biosensors by doping ionic liquid and catalyst into a conductive polymer (poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), PEDOT:PSS).

An enzyme-mediated bioorthogonal labeling method for genome-wide mapping of 5-hydroxymethyluracil.

DNA 5-hydroxymethyluracil (5hmU) is a thymine modification existing in the genomes of various organisms. The post-replicative formation of 5hmU occurs hydroxylation of thymine by ten-eleven translocation (TET) dioxygenases in mammals and J-binding proteins (JBPs) in protozoans, respectively. In addition, 5hmU can also be generated through oxidation of thymine by reactive oxygen species or deamination of 5hmC by cytidine deaminase.

A ratiometric photoelectrochemical microsensor based on a small-molecule organic semiconductor for reliable analysis.

Photoelectrochemical (PEC) sensing has been developing quickly in recent years, while its application is still in the infancy. The complexity of biological environments poses a high challenge to the specificity and reliability of PEC sensing. We herein proposed the concept of small-molecule organic semiconductor (SMOS)-based ratiometric PEC sensing making use of the structural flexibility as well as readily tunable energy band of SMOS.

Direct decarboxylation of ten-eleven translocation-produced 5-carboxylcytosine in mammalian genomes forms a new mechanism for active DNA demethylation.

DNA cytosine methylation (5-methylcytosine, 5mC) is the most important epigenetic mark in higher eukaryotes. 5mC in genomes is dynamically controlled by writers and erasers. DNA (cytosine-5)-methyltransferases (DNMTs) are responsible for the generation and maintenance of 5mC in genomes.